DETAILED DESCRIPTION OF THE INVENTION

[0028] Unless otherwise indicated, all numbers or expressions referring to quantities of ingredients, reaction conditions, etc., used herein are to be understood as modified in all instances by the term “about.”

[0029] Various numerical ranges are disclosed in this patent application. Because these ranges are continuous, they include every value between the minimum and maximum values. Unless expressly indicated otherwise, the various numerical ranges specified in this application are approximations.

[0030] As used herein and in the claims, the term “superabsorbent polymer” refers to any suitable natural or synthetic polymeric material in a dry form that is capable of absorbing and storing many times its weight in water. After absorbing water, the superabsorbent polymer takes on a particulate, jelly-like or hydrogel form, but remains in a non-flowable state.

[0031] As used herein and in the claims, the term “water-resistant” refers to materials that generally repel or resist penetration by water through the material where the materials are not entirely waterproof. In other words, water-resistant materials generally hinder the penetration of water through their fabric and provide a water-repellent barrier.

[0032] As used herein and in the claims, the term “water wickable thread” refers to any suitable fiber that is capable of conveying water and/or aqueous solutions by capillary action. In other words, a water wickable thread useful in the present invention may include, but is not limited to, any fiber, bundle of fibers, or loosely twisted, braided, or woven cord, tape, or tube that by capillary attraction draws water from one location to another.

[0033] As used herein and in the claims, the term “cooling garment” refers to any suitable fabric, piece of fabric, article of clothing, or other article that is capable of transfering heat from the body of a human and/or an animal. Suitable articles that the term cooling garment includes are, without limitation, blankets, capes, vests, scarfs, neckerchiefs, caps, hats, headbands, do rags, and other headware or other systems.

[0034] The present invention provides a cooling garment that includes an upper layer that contains a water-resistant fabric, a lower layer that contains a water-resistant fabric, a plurality of chambers disposed between the upper layer and the lower layer formed by stitching the upper layer and the lower layer together using a water wickable thread, and a superabsorbent polymer contained within a majority of the chambers.

[0035] The present cooling garment is made, at least in part, using a cooling fabric as shown in FIGS. 1 - 4 . The cooling fabric 10 includes a plurality of chambers 11 , that are defined by an upper layer 12 , a lower layer 14 and edges defined by the stitched pattern of a water wickable thread 18 . Chamber 11 contains superabsorbent polymer particles 16 .

[0036] When used as a cooling garment or as part of a cooling garment, superabsorbent polymer 16 in chamber 11 is exposed to and adsorbs or is hydrated by water or an aqueous solution. Once the superabsorbent polymer 16 has been hydrated, when cooling fabric 10 is placed against the skin of a human or animal, it actively acts to draw heat or thermal energy from the skin, cooling the wearer.

[0037] Although not being limited to any one theory, it is believed that when cooling garments containing the above-described cooling fabric are draped or worn or placed in proximity of a human or animal body, the evaporative effects of the hydrated superabsorbent polymer provide convective or conductive cooling.

[0038] Hydration of superabsorbent polymer 16 is accomplished by placing or otherwise contacting cooling fabric 10 with water or an aqueous solution. As FIG. 3 shows, water does not directly enter chamber 11 through upper layer 12 or lower layer 14 because each layer contains a water-resistant material. As indicated by the arrows in FIG. 3 , water or an aqueous solution is conveyed by water wickable thread 18 to chamber 11 . Once the water or aqueous solution has entered chamber 11 , it is absorbed by superabsorbent polymer 16 , which expands from its dry state as shown in FIG. 3 to its enlarged hydrated state as shown in FIG. 4 . Typically, superabsorbent polymer 16 absorbs enough water or aqueous solution to expand and fill the volume of chamber 11 .

[0039] In an embodiment of the present invention, holes created by sewing and stitching upper layer 12 to lower layer 14 provide a pathway for water or aqueous solution to be conveyed into chamber 11 . In this embodiment, thread 18 may or may not be of a water wickable construction.

[0040] The cooling fabric can be used to make any suitable type of cooling garment known in the art. Suitable cooling garments include, but are not limited to, blankets, capes, vests, scarfs, neckerchiefs, caps, hats, headbands, do rags, and other headware or other systems.

[0041] In a non-limiting embodiment of the present invention, the cooling garment may be a first vest as shown in FIG. 5 . First vest 20 includes the above-described cooling fabric in the areas of first vest 20 that contact the chest, neck, and upper back of the wearer. The chambers 24 are defined by the stitching pattern of water wickable thread 22 . First vest 20 may be closed by fastening buttons 26 through button holes 28 . As shown in FIG. 5 , the portion of first vest 20 that would be in contact with the lower back and waist area of the wearer does not include chambers 24 defined by a stitching pattern of water wickable thread 22 . This portion of first vest 20 may be constructed of the present cooling fabric without any superabsorbent polymer being present in chambers 24 , or alternatively, this portion of first vest 20 may be constructed of another fabric, which may or may not be water-resistant. Examples of non-water-resistant fabrics that may be used include, but are not limited to, cotton, wool, nylon, rayon, acrylics, and fabric blends as are well known in the art.

[0042] In another non-limiting embodiment of the present invention, the cooling garment may be a second vest as shown in FIG. 6A . Second vest 30 includes the above-described cooling fabric in the areas of second vest 30 that contact the shoulders, upper back and lower torso of the wearer. Chambers 34 extend laterally and are defined by the stitching pattern of water wickable thread 32 . Second vest 30 may be closed by fastening a VELCRO® fastener 36 (Velcro Industries B. V., Curacao, AN). Further to this embodiment as shown in FIG. 6 B, which includes the features described in FIG. 6A above, the second vest 30 may include light reflective material 38 positioned so as to encircle the chest and waist areas when the vest is worn.

[0043] In an additional non-limiting embodiment of the present invention, the cooling garment is a cap as shown in FIG. 7 . Cap 40 may be entirely constructed of the above-described cooling fabric. Cap 40 generally includes a dome portion 44 and a headband portion 46 . Dome portion 44 and headband portion 46 may be individual chambers defined by the stitching pattern of water wickable thread 42 .

[0044] In a further non-limiting embodiment of the present invention, the cooling garment is a headband as shown in FIG. 8 . Headband 50 includes the above-described cooling fabric in the areas of headband 50 that contact the front and sides of the forehead of the wearer. The chambers 54 are defined by the stitching pattern of water wickable thread 52 .

[0045] In a further additional non-limiting embodiment of the present invention, the cooling garment is a hat as shown in FIG. 9 . Hat 60 may be entirely constructed of the above-described cooling fabric. Hat 60 generally includes a dome portion 44 , a headband portion 66 , ear flap portions 67 , and back flap portion 68 . The chambers in hat 60 are defined by the stitching pattern of water wickable thread 62 .

[0046] In another non-limiting embodiment of the present invention, the cooling garment may be a fourth vest as shown in FIG. 10 . Fourth vest 70 includes the above-described cooling fabric in the areas of fourth vest 70 that contact the shoulders, upper back, and lower torso of the wearer. Chambers 74 extend laterally and are defined by the stitching pattern of water wickable thread 72 . Fourth vest 70 may be closed by fastening a VELCRO® fastener 76 .

[0047] In the above-described cooling fabric, the upper layer and the lower layer may be made using any suitable water-resistant fabric. Suitable water-resistant fabrics of the upper layer and the lower layer may independently include, but not be limited to, fabrics containing one or more fibers selected from polyamides, polyesters, polyurethanes, vinyl, acrylic, fluoropolymers, and aramid materials.

[0048] Specific examples of suitable fibers and fabrics that may be used to make the upper layer and/or the lower layer of the cooling fabric include, but are not limited to, the segmented polyurethanes available under the trade name Lycra® from E. I. du Pont de Nemours and Company, Wilmington, Del.; the solution dyed polyester fabric with a urethane coating available as Sur Last™ all weather fabric from Sur Last, Indianapolis, Ind.; the coated fabrics available under the name Hydro-No from Norsk Hydro, Oslo, Norway; Power-Tex® available from GLAMORISE FOUNDATIONS, INC., New York, N.Y.; Ultrex® available from Burlington Performance Wear, GREENSBORO, N.C.; nylon or polyester coated with a polyurethane-based coating available as Hydroflex® from Consoltex, Saint-Laurent, Quebec; Demizax®, H2OFF®, REPLEX®, and Entrant G-11® materials available from Toray Industries, Inc., New York, N.Y.; the Fluoro Carbon fiber Toyoflon™ available from ToRay Industries; the Aramid fibers Kevlar® and NOMEX® available from DuPont; ARAFLEX® available from Second Chance Body Armor, Inc., Central Lake, Mich.; Twaron® available from AKZO NOBEL, Inc.; BASOFIL® fibers commercially available from BASF, Charlotte, N.C.; the poly(p-phenylene-2,6-benzobisoxazole) (PBO) sold under the trademark ZYLON® by Toyobo Co. Ltd., Osaka, Japan; and composites such as those described in U.S. Pat. No. 6,261,678 to von Fragstein et al.

[0049] In an embodiment of the present invention, the fabrics used to make the upper layer and the lower layer of the cooling fabric are comprised of one or more fabrics containing fibers comprised of materials selected from polyamides, polyesters, polyurethanes, vinyl, acrylic, fluoropolymers, aramid, poly(p-phenylene-2,6-benzobisthiazole), and poly(p-phenylene-2,6-benzobisoxazole).

[0050] The fabrics used to make the upper layer and the lower layer of the cooling fabric and/or the lower layer of the cooling fabric may have any suitable thread count. As used herein and in the claims, the term “thread count” is the number of horizontal and vertical threads in one square inch of fabric. The fabrics of the present invention may have a thread count of at least 50, in some cases at least 70, in other cases at least 80, and in other cases at least 100 threads per square inch. Further, the fabrics of the present invention may have a thread count of up to 350, in some cases up to 300, in other cases up to 250, in some situations up to 200, and in other situations up to 150 threads per square inch. The thread count of the fabrics in the upper layer and in the lower layer may vary between any of the values recited above.

[0051] The fabrics used to make the upper layer and the lower layer of the cooling fabric and/or the lower layer of the cooling fabric may have any suitable degree of thickness or fineness. The fineness of a fabric is measured by its denier, a unit of fineness equal to the fineness of a fiber weighing one gram for each 9000 meters. A fiber of <100 denier is finer than a 150 denier fiber.

[0052] The water-resistant fabric of the upper layer and the lower layer has a total denier of at least 30, in some situations at least 40, in other situations at least 50, in some cases at least 60, and in other cases at least 70. The total denier of the water-resistant fabric may be up to 500, in some cases up to 400, in other cases up to 300, in some situations up to 200, and in other situations up to 100. When the total denier is too low, the properties of the fabric may be unsatisfactory. The total denier of the water-resistant fabrics in the upper layer and in the lower layer may vary between any of the values recited above.

[0053] In general, the denier of a single fiber used in the water-resistant fabric is at least 1, in some cases at least 2, in other cases at least 3, and in some situation at least 4. Further, the denier of a single fiber used in the water-resistant fabric may be up to 15, in some cases up to 12, in other cases up to 10, and in other cases up to 8. The denier of a single fiber used in the water-resistant fabrics in the upper layer and in the lower layer may vary between any of the values recited above.

[0054] Typically, the strength of a single fiber used in the water-resistant fabric is at least 0.5 g/denier, in some cases at least 1 g/denier, and in other cases at least 2 g/denier or more.

[0055] In an embodiment of the present invention, the water-resistant fabric of the upper and/or lower layers has a Moisture Vapor Transmission Rate (MVTR) of less than 500 g/m ² per 24 hours, in some cases less than 400 g/m ² per 24 hours, in other cases less than 300 g/m ² per 24 hours, in some situations less than 200 g/m ² per 24 hours, and in other situations less than 100 g/m ² per 24 hours. If the MVTR is too high, the superabsobent polymer may dehydrate (lose its water content) too quickly and require re-hydration too frequently. Additionally, although not required, it may be desirable that the water-resistant material have some measurable MVTR, so that the cooling fabric and/or cooling garments containing the cooling fabric may be dried (the superabsorbent polymer dehydrated) when desired. As such, the water-resistant fabric of the upper and lower layers may have an MVTR of at least 0.1 g/m ² per 24 hours, in some cases at least 1 g/m ² per 24 hours, in other cases at least 5 g/m ² per 24 hours, in some situations at least 10 g/m ² per 24 hours, and in other situations at least 25 g/m ² per 24 hours. The MVTR of the water-resistant fabric of the upper layer and/or lower layer may vary between any of the values recited above.

[0056] As used herein and in the claims, the MVTR of the water-resistant fabric is determined by the following procedure. Approximately 70 ml of a solution consisting of 35 parts by weight of potassium acetate and 15 parts by weight of distilled water are placed into a 133 ml polypropylene cup having an inside diameter of 6.5 cm at its mount. An expanded polytetrafluoroethylene (PTFE) film having a minimum MVTR of approximately 60,000 g/m ² per 24 hours as tested by the method described in U.S. Pat. No. 4,862,730 to Crosby using potassium acetate and available from W. L. Gore & Associates, Inc. of Newark, Del. is heat sealed to the lip of the cup to create a taut, leakproof, microporous barrier containing the solution. A similar expanded PTFE film was mounted to the surface of a water bath. The water bath assembly is controlled at 23±0.2° C. utilizing a temperature-controlled roll and a water circulating bath. The sample to be tested is allowed to condition at a temperature of 23° C. and a relative humidity of 50% prior to performing the test procedure. Samples are placed so that the water-resistant fabric to be tested is in contact with the expanded polytetrafluoroethylene film mounted to the surface of the water bath and an equilibration of at least 15 minutes is used prior to the introduction of the cup assembly. The cup assembly is weighed to the nearest 0.001 g and is placed in an inverted manner onto the center of the test sample. Water transport is provided by the driving force between the water in the water bath and the saturated salt solution providing water flux by diffusion in that direction. The sample is tested for 15 minutes and the cup assembly is then removed and weighed again. The MVTR is calculated from the weight gain of the cup assembly and expressed in grams of water per square meter of sample surface area per 24 hours.

[0057] In a particular embodiment of the present invention, the cooling fabric used for one or both of the upper layer and the lower layer is a fabric that includes a substrate fabric, which may include any of the fabrics or fiber based materials described above, and a water-resistant coating layer formed from a water-resistant coating composition over at least a portion of a surface of the substrate fabric. Any suitable coating composition can be used to form the coating layer. Suitable coating compositions include, but are not limited to, those that include one or more water-resistant materials selected from natural rubber, synthetic rubber, silicone rubber, fluoropolymers, polyurethanes, and acrylics.

[0058] In an embodiment of the present invention, a coated fabric useful as either or both of the upper layer and the lower layer is produced as follows. First, a woven fabric is constructed or obtained that is suitable for use in the present cooling fabric. As described above, the fabric may be made from any of the suitable materials described above. Prior to applying a water-resistant composition, the fabric may be scoured. When scoured, the material may be scoured with an alkaline solution.

[0059] In some cases, after being scoured, the fabric is put on a tenter frame, dried and heat set. In some situations, it is advantageous that the fabric be substantially dry and free of moisture prior to being treated with the water-resistant composition. As a non-limiting example, the fabric may be dried so that the moisture level is substantially equivalent to the natural moisture level of the fibers used to make the fabric. For many fibers, the moisture level should be less than 10%, and in some cases less than 7%.

[0060] After the fabric has been dried and heat set, the water-resistant composition is applied to at least one side of the fabric. The composition may be sprayed on the fabric, printed on the fabric, and/or the fabric is dipped into a bath containing the water-resistant composition in solution, dispersion, or emulsion form.

[0061] After the water-resistant composition is applied to the fabric, the fabric may be heated to a temperature sufficient for the coating to dry and/or cure. Once the water-resistant composition has been sufficiently heat treated, the fabric may be used in constructing the cooling garments in accordance with the present invention.

[0062] The water-resistant materials can be combined in water with a drying agent such as an alcohol and an emulsifier. The amount of the water-resistant composition applied to the fabric will depend upon the particular formulation and the particular application method.

[0063] In an embodiment of the present invention, the water-resistant material comprises a fluorocarbon, an acrylic polymer, and/or a polyurethane.

[0064] When the cooling fabric used for one or both of the upper layer and the lower layer is a fabric and includes a substrate fabric coated by a water-resistant coating layer, the substrate fabric may comprise one or more fabrics containing fibers comprised of materials selected from cotton, wool, polyamides, polyesters, polyurethanes, vinyl, acrylic, fluoropolymers, aramid, poly(p-phenylene-2,6-benzobisthiazole), and poly(p-phenylene-2,6-benzobisoxazole) or any other fabric described above.

[0065] As was indicated above, a water wickable thread may be used to sew and/or stitch the upper layer and the lower layer together to form a plurality of chambers. Any suitable water wickable thread may be used in the present invention. Examples of suitable materials from which the wickable thread may be made include, but are not limited to, cotton, wool, hemp, copolyetheresters, polyesters, polyethers, and mixtures thereof.

[0066] The chambers formed in the present cooling garments may be dimensioned to form any suitable type of shape. Suitable shapes include, but are not limited to, squares, rectangles, triangles, circles, and ovals, as well as non-descriptive shapes, so long as the stitching forms a continuous barrier to contain and hold the superabsorbent polymer in place. The shape of the chambers may be dimensioned to encompass an area in the upper layer and/or the lower layer of at least 1 mm ² , in some cases at least 2 mm ² , in other cases at least 3 mm ² , in some situations at least 5 mm ² , and in in other situations at least 10 mm ² . When the area of the chambers are too small, the cooling fabric may have poor heat transfer properties. Further, the chambers may be dimensioned to encompass an area of up to 60 mm ² , in some cases up to 55 mm ² , in other cases up to 50 mm ² , in some situations up to 45 mm ² , in other situations up to 40 mm ² , in some circumstances up to 35 mm ² , and in other circumstances up to 25 mm ² . When the area of the chambers is too large, the superabsorbent polymer particles may settle to the lower portions of the chamber and provide insufficient heat transfer properties to the cooling garment. The chambers of the cooling garment may have an area between any range of values inclusive of those stated above.

[0067] In a particular embodiment of the present invention, the water-resistant fabric of the upper layer and/or the lower layer comprises nylon, has a 70×70 warp/filling, has a 104×86 thread count, has one side coated by a coating composition comprising a polyurethane, and the other side coated by a coating composition comprising an acrylic polymer. In this embodiment, either side may be the side in contact with the superabsorbent polymer and either side may be the side in contact with skin, clothing or the atmosphere.

[0068] As indicated above, the chambers contain a superabsorbent polymer. Any suitable superabsorbent polymer may be used in the present cooling garment. Suitable superabsorbent polymers include, but are not limited to, natural gums, cellulosics, synthetic hydrogel polymers, and mixtures thereof.

[0069] In an embodiment of the present invention, the natural gums useful as superabsorbent polymers may be selected without limitation from xanthan, guar, agar, pectin, gum arabic, locust bean gum, hydroxypropyl guar gum, polyglucomannan gum, cationic guar gum, anionic guar gum, alginate, irish moss, and gum arabic. The cellulosics useful as superabsorbent polymers may be selected without limitation from methyl cellulose, ethyl cellulose, carboxymethyl cellulose, carboxy ethyl cellulose, hydroxyethyl cellulose, hydroxymethyl cellulose, and hydroxypropylcellulose. The synthetic hydrogel polymers useful as superabsorbent polymers may be selected without limitation from suitable crosslinked, water-swellable acrylic copolymers.

[0070] In a particular embodiment of the present invention, the synthetic hydrogel polymers include, but are not limited to, copolymers that include repeat units from one or more monomers selected from (meth)acrylic acid, maleic acid, 2-(meth)acrylamido-2-methyl propane sulfonic acid, styrene sulfonate, vinyl sulfonic acid, and their corresponding ammonia, amine and alkali metal salts, (meth)acrylamide, vinyl alcohol, vinyl acetate, maleic anhydride, alkyl vinyl ethers, vinylmorpholinone, vinylpyrridine, vinyl pyrrolidone, and acrylonitrile; and one or more crosslinking agents selected from N,N′-methylenebis(meth)acrylamide, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, glycerol tri(meth)acrylate, glycerol acrylate methacrylate, ethylene-oxide-modified trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, triallyl cyanurate, triallyl isocyanurate, triallyl phosphate, triallylamine, poly(meth)allyloxyalkanes, (poly)ethylene glycol diglycidyl ether, glycerol diglycidyl ether, ethylene glycol, polyethylene glycol, propylene glycol, glycerol, pentaerythritol, ethylenediamine, ethylene carbonate, propylene carbonate, polyethylenimine, glycidyl (meth)acrylate, diallyl sucrose, triallyl sucrose triallyl amine, and triallyl methyl ammonium chloride.

[0071] In another particular embodiment of the present invention, the superabsorbent polymer comprises a synthetic anionic acrylic copolymer.

[0072] Additional superabsorbent polymers and methods to manufacture such polymers are described, without limitation, in U.S. Pat. No. 6,469,080 to Miyake et al., U.S. Pat. No. 6,399,668 Miyake et al., U.S. Pat. No. 6,127,454 to Wada et al., U.S. Pat. No. 6,087,002 to Kimura et al., U.S. Pat. No. 5,244,735 to Kimura et al., U.S. Pat. No. 4,925,603 to Nambu, and U.S. Pat. No. 4,734,478 to Tsubakimoto et al. Non-limiting examples of superabsorbent polymers that may be used in the present cooling garment include those available under the trade names ALCOSORB® from Ciba Specialty Chemicals, Chatanooga, Tenn.; DRYTECH® from the Dow Chemical Company, Midland, Mich.; NORSOCRYL® and AQUAKEEP® from Atofina, Paris, France; HYDROSORB™ from HYDROSORB Inc., Orange, Calif.; and AQUALIC CA from Nippon, Shokubai Co., Ltd., Osaka, Japan.

[0073] The superabsorbent polymer, when dry, is typically in particulate form. The particle size of the superabsorbent polymer particulates are typically at least 20 microns, in some cases at least 35 microns, in other cases at least 50 microns, and in certain situations at least 100 microns. It is desirable that the particle size of the superabsorbent polymer particulates be large enough that they can be contained in the fabric. Further, the particle size of the superabsorbent polymer particulates is up to 1,000 microns, in some cases up to 750 microns, in other cases up to 500 microns, and in certain situations up to 350 microns. If the particle size of the superabsorbent polymer particulates is too large, they may take too long to hydrate effectively. The particle size of the superabsorbent polymer particulates may vary between any of the values recited above.

[0074] The cooling garment of the present invention may be made entirely of the cooling fabric described above. Alternatively, the cooling garment may be constructed in part using the present cooling fabric and the remainder constructed of any suitable conventional fabric. Suitable conventional fabrics include, but are not limited to, those including cotton, wool, nylon, and other materials known in the art.

[0075] The cooling garments described above, once hydrated (i.e., the superabsorbent polymer is hydrated), maintain their moisture level and cooling capacity for a week or more when left hanging at ambient conditions. In other words, because of the fabric selection and/or fabric coating, the fabric is water-resistant and the superabsorbent polymer particles retain their moisture and do not dry out as quickly as when non-water-resistant fabrics are used as the upper layer and/or lower layer of the cooling garment. Further, moisture, water, or aqueous solutions absorbed by the superabsorbent polymer do not “wick out” or transfer to the skin or clothing of the wearer.

[0076] The invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of appended claims or the equivalents thereof.